


I think, therefore

by Tashilover



Category: Cabin Pressure, Sherlock (TV)
Genre: Crossover, body switch
Language: English
Status: Completed
Published: 2013-05-31
Updated: 2013-11-11
Packaged: 2017-12-13 12:23:15
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,168
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/824278
Author URL: https://archiveofourown.org/users/Tashilover/pseuds/Tashilover
Summary: <blockquote class="userstuff">
              <p>Martin doesn't know what's going on. Neither does John.</p>
            </blockquote>





	1. Chapter 1

His first clue should have been the temperature. While Martin's attic wasn't exactly an igloo, during the winter it was easily the coldest room in the whole house, forcing Martin to sleep under two thick blankets. He wasn't cold.

He was too comfortable to notice how the temperature felt. Too comfortable to notice his blankets were not as heavy, to notice how his pajamas were a bit too thin and his bed a bit too wide.

The smell of fresh coffee tickled his nostrils and that slowly roused him. Very rarely did the smells of the kitchen ever permeated upwards to the attic. If there was coffee, it was never for Martin. Confused, he opened his eyes.

 

 

 

 

John nearly dropped his mug when the screaming started. "Sherlock?" He said, pushing aside his mug, uncaring he sloshed the coffee all over the table. "Sherlock?"

He dashed across the flat, throwing himself against Sherlock's bedroom door, bursting through. He half-expected blood and gore and possibly a dead flatmate. Instead, he found Sherlock standing against a corner, looking wildly confused. "Where am I?" He said wildly.

"You're at home," John said, peering around to see if there was someone else in the room. "What's going on? Why were you screaming?"

This didn't seem to calm Sherlock down. " _Home_?" He squealed. "This isn't... who are you?"

Oh crap, John internally groaned. Was Sherlock sick? Was he hallucinating? "Sherlock-" John began, stepping forward.

"Stay back," Sherlock hissed, throwing up his hands. "I mean it."

"Okay," John backed off. He thought about texting Mycroft, asking him if this was normal. He decided against it as soon as he thought of it. He won't contact Mycroft unless it was absolutely necessary. "Look, I'm going back out into the kitchen. That's where I'll be waiting with a fresh pot of coffee. When you're ready to come out..."

John waited patiently at the kitchen table, keeping his eyes on Sherlock's bedroom door. Mentally he was going through several diagnoses, trying to figure out why his friend was suddenly having a mental breakdown. The only thing that kept coming to mind was morning amnesia. A common occurance among men, but it should only last for no longer than two minutes after waking up. This... was something different.

John hoped it wasn't drugs.

Sherlock emerged from his room five minutes later, his body tense in a way that told John he was ready to run if need be. His eyes darted around the flat like he's never seen it before in his life. He didn't change out of his clothes to something more presentable. The only thing he put on were a pair of shoes.

John held up a mug. "Coffee?"

Sherlock didn't care much for coffee, preferring tea, nicotine, and pure inner-will to keep him awake. He would only have coffee if there was nothing better avaliable.

But  _this_  Sherlock didn't shy away at the prospect of coffee. Instead, he sat down and mutely accepted the mug given to him. He muttered a soft, "Thank you," before taking a deep sip.

He sighed in contentment. "This is good," he said.

John tried to rationalize this. Was his friend trying out a new character? Sometimes Sherlock acted out different personalities, trying to refine them so he could use them in the future. But he always did it in costume and he always changed his voice.

"Are you alright?" John asked. Best get the neutral questions out of the way.

Sherlock lowered his mug. Bit his lip, then shook his head. "I believe I might be dreaming."

"Oh. What makes you think you are dreaming?"

He was tugging at his locks, running his fingers through them, almost grimacing. "I don't keep my hair this long," he began. "And it's black. And I'm... taller."

Well, this was new. "You're taller? By how much?"

"Nearly... oh... er... six inches."

John snorted out a laugh. "What, are you serious?"

Sherlock made a face. "Well, excuse me," he mumbled as he took another sip of coffee.

This had to be Sherlock's new way of character development. That only meant one thing: either John could play along and help Sherlock develop this personality of a short man, or John could fight it every inch of the way and develop a stress headache for his troubles.

It was easier to play along. "Alright then," John said. "What's your name?"

"M-Martin," Sherlock said, nearly suttering. "Martin Crieff."


	2. Chapter 2

_Martin Crieff_  fidgeted in his chair while John made breakfast. He was a lot calmer now that he had his coffee, but that didn't stop him from looking at the flat like he'd never seen it before in his life. When Martin noticed the skull on the fire mantle, his eyes bugged out.

When John took out the bacon from the fridge, he angled his body so Martin wouldn't see the severed fingers the bacon sat next to. John really didn't want to find out how the character Martin reacted to detached human body parts.

"Where am I?" Martin asked suddenly. "What's the address?"

"221 B, Baker Street." At Martin's face, John added on, "Er... London, England?"

" _London_?" Martin squealed. He jumped up from his chair and dashed to the windows, throwing open the curtains and looking outside. He yelped. "London! London! Why am I in London? What kind of dream is this?"

"Whoa, whoa, settle down."

"London..." Martin moaned, stepping back from the windows and collapsing into the nearest chair. "This is... Douglas."

It was like a lightbulb turned on above his head. You could hear the revelation in his voice. "Douglas!" He said again. "I'll call Douglas, he'll know what to do!"

He reached for the phone sitting on the living room table. He turned it on and immediately frowned. "Um..." Martin turned to John. "I don't know the password..."

Very clever of Sherlock, locking the phone before going into this character phase. But locking  _a_  phone was not going to stop this Martin fellow if he was persistent. There were still phone booths, disposable phones, internet...

"I don't know the password either," John said truthfully.

"Oh. Um... may I use your phone?"

Should John say yes? Or no? Curious to see how Sherlock would overcome such an obstacle, John said, "Sure."

He took a moment to clean his hands of bacon grease, dug out his phone from his back pocket and tossed it to Martin.

Martin turned it on. "Um... sorry, but what's  _your_  password?"

"My password? I didn't put a lock on my phone."

"You did," Martin said, turning the phone around to show him. There was indeed a password lock. "See?"

John gaped. Did Sherlock really lock  _his_  phone without telling him? "That son of a bitch!"

Martin flinched. "Sorry," John said, turning back around to finish cooking. "But it seems my previous flatmate is playing a trick on me. I don't know the password to my phone."

"Is there a landline I can use?"

In Mrs. Hudson's flat there used to be one. Until Sherlock melted her phone in an experiment. He ended up buying her a smart phone in apology. "No, sorry. Look, it's nearly ten. How about we have breakfast first and think about phone calls later? Hhmmm?"

The mention of breakfast seemed to perk Martin up. "Can I help?" He asked sincerly.

John had to pause. Sherlock never offered his help. John should record this for future evidence. "Huh... sure. Why don't you start on the eggs?"

He pointed to a few eggs sitting in a mixing bowl.

Martin was almost delighted to be doing something. When he went to the bowl, John heard him mutter, "Wow, eggs too?"

Maybe this wasn't just an experiment for Sherlock, but a deducing test for John. Because from the way Martin said it, it sounded like Martin hardly ever got the chance to have eggs or bacon.

"So, huh... Martin, what do you do for a living?" John asked.

"I'm a Airline Captain," Martin said proudly.

Airline Captain. Don't those blokes make really good wages though? Strange profession Sherlock chose for such a twitchy guy. "An airline captain? That's impressive, considering your age."

It sounded rude. But Martin seemed to experience such comments before and didn't take offense. "I know. A lot of people don't believe me, even when I'm wearing my uniform. It's actually pretty annoying. I mean, I know I'm short and young and when I'm standing next to Douglas, who is tall and handsome and actually  _sounds_  like a captain with the way he looks and talks and acts. I mean, age and height does not equal a captain! If that's true, then taxi-driver Martin would be a captain and I would be just a man with a van!"

John continued to cook the bacon uncomfortably. Now he was sorry he asked.

"Sorry," Martin said, pouring the eggs into a pan to cook them. "I get a lot of disbelief and it makes me... defensive."

John didn't answer and concentrated his efforts on cooking. Once again, this Martin character was too twitchy to be a pilot. Either he was lying or someone made a terrible mistake in hiring him.

Despite the upset, breakfast was a decent affair. When he wasn't twitchy, Martin was actually a decent conversationalist. While they ate, he entertained John with the crazy trips of MJN. John was impressed by the amount of detail Sherlock had put into this character. Carolyn, Arthur and Douglas sounded like real people.

Once they finished eating and John placed away their plates in the sink, Mrs. Hudson knocked on their front door, letting herself in. "Good morning, boys," she said.

Martin responded with, "G-good morning."

"Oh, Sherlock darling, that lovely inspector just called. He said he's coming to pick you and John up. Apparently somebody was decapitated this morning." Mrs. Hudson said gleefully.

Martin paled. "W-w-w-what?"

John covered his mouth with his hand, trying not to laugh, but as Mrs. Hudson helped place away the milk she said, "Sherlock, would you stop placing human fingers in the fridge? People will think you're deviants."

Martin looked even worse. "What...?"

"Thank you, Mrs. Hudson," John said, trying to lead her out of the flat. She shouldn't be involved with Sherlock's role playing. "We're going to get ready now."

"Alright boys, I'll give you your privacy." She studied Martin's face for a moment, humming thoughtfully. "You look a bit peaky, dear. John, do check his temperature."

The moment Mrs. Hudson left, Martin went straight for the fridge. John jumped out of his chair,  _lunged_ , banged his shin against a table leg and threw his back against the fridge door. "Don't," John warned. "You don't want to see."

"Are you serial killers?" Martin asked fearfully. He was getting paler by the second. "Am I in a murder house?"

"What? No! You're... I'm... My friend is a detective. He works for the police and sometimes he brings his work home."

Martin was slowly inching his way towards the door. "Right..."

Martin was shoeless, still wearing Sherlock's robe, in his pyjamas, and he ran for it. John cursed, forced himself off the fridge and went after him. Martin was already down by the stairs, hands stretched out to open the front door.

He tripped on the last stair, crashing into the coat rack.

"Sherlock!" John yelled, stomping down as fast and carefully as he could. "This is enough! Stop this!"

Martin surged to his feet, grunting and visibly in pain, and tried to go for the door again. John was on him by then, tackling him around the torso, and the both of them fell to the floor with a crash.

"Get off me!" Martin was yelling, screaming. He was trying to get John off, kicking and smacking him over the head. John held strong and tried to drag him back into the hallway. "Get off of me you weirdo!"

"Sherlock-!"

"HELP!" Martin screamed towards the door. "SOMEONE, HELP ME!"

"Dammit, Sherlock, that is enough-!"

The door swung opened. John froze, his mind flashing mock newspaper articles of himself getting arrested because Sherlock called him a serial killer.

A tall man stepped through, saw them on the floor and said, "Good heavens! I can't believe it."

"Douglas?" Martin gasped underneath John's weight. "DOUGLAS!"

John's mouth fell opened. What was-?

The man, Douglas, was suddenly shoved to the side as a smaller man elbowed him in the gut to move him out of the way. In this light, it was hard to see but... he looked exactly like Sherlock. Just shorter, thinner, wearing a pilot's outfit and had red hair. He was also scowling heavily like he just found out he stepped on animal dung.

"John," the Sherlock-man said. "Get off of Martin. I've had a  _long_  morning with an idiot-man child, an incorrigible old woman, this know-it-all here-" he said, jabbing a thumb to the taller man besides him. "- and I am not in the mood to find bruises on my body. So please, get off of him."

**Author's Note:**

> I swore I would never do a CP/Sherlock crossover. Then this happened. Woop.


End file.
